5-minute 3D printed bioreactor offers better way to make drugs, booze

Jul 7, 2017 | By Benedict

Alshakim Nelson and fellow chemists at Seattle’s University of Washington have developed a 3D printed, yeast-based bioreactor that can keep on fermenting for months at a time. Nelson’s team built a 3D printer specifically for the purpose of fabricating such bioreactors.

Yeast, an inconspicuous fungus, has proved itself an incredibly important substance in human civilization. We use it to make bread, wine, and beer, amongst other things. But since learning about the practical function of yeast several millennia ago, humans have discovered other ways to harness the power of fermentation. Mold and bacteria can now be used to create things that are even more useful than beer: medicinal drugs, for example.

These days, fermentation is an exact science, a far cry from what the ancient Egyptians were doing to make bread and alcoholic drinks. (Though making bread and beer is arguably just as important as experimental science.) Special bioreactors are now used to control the fermentation of organic substances in order to create complex substances, and fermentation is an important area of study for chemists.

Thanks to the work of Alshakim Nelson, a chemist at Seattle’s University of Washington, fermentation could be about to become a lot cheaper, more accessible, and more efficient than ever before. That’s because the scientist’s laboratory has designed a special 3D printer that can churn out bioreactors in just five minutes. And these aren’t the 3D printed Yoda heads of bioreactors; the 3D printed apparatuses are incredibly effective, lasting for (at least) several months at a time.

According to the Washington chemists, the 3D printer used to create these bioreactors lays down thin strips of hydrogel in a cubic lattice structure. This cube, which measures roughly a cubic centimeter, can then be cured by ultraviolet light to increase its rigidity.

The hydrogel used to create these 3D printed bioreactors is made up of around 70 percent water, with the remaining 30 percent made up of a special polymer infused with yeast. The hydrogel can be easily extruded through the nozzle of the 3D printer, allowing for the cubes to be precisely printed without error.

When these 3D printed cubes are placed in glucose, the yeast in the bioreactor turns the glucose into ethanol—just like a brewery does. And amazingly, it can do this for a long, long time. Nelson says that, as long as the fermented solution is regularly replaced with a fresh batch, the 3D printed bioreactors can go on and on.

At present, the 3D printed cubes have been going for four months—and they’re showing no signs of giving up.

The Seattle-based chemists have clearly stumbled upon something very useful, but—funnily enough—they’re not entirely sure how to explain what they’ve done. Nelson believes that the immobilization of the yeast cells in the hydrogel may stop them aging and reproducing, while maintaining their ability to ferment, but the exact reasons for the longevity of these printed wonder reactors have not yet been nailed down.

However they work, Nelson’s 3D printed yeast bioreactors have huge potential. Larger versions of the cubes could hypothetically replace the batch-processing approach used in many kinds of fermentation, while the bioreactors could even be altered to produce substances besides ethanol. Proteins, for example.